W3C home > Mailing lists > Public > xml-uri@w3.org > May 2000

Fw: Welcome to the XML-URI list

From: Michael Champion <Mike.Champion@softwareag-usa.com>
Date: Mon, 15 May 2000 13:30:52 -0400
Message-ID: <044601bfbe93$52082a40$39daa318@WORKGROUP>
To: <xml-uri@w3.org>

----- Original Message -----
From: "Tim Berners-Lee" <timbl@w3.org>
To: <xml-uri@w3.org>
Cc: <xml-dev@xml.org>
Sent: Monday, May 15, 2000 9:45 AM
Subject: Welcome to the XML-URI list

> Finally a note about the alternatives to using URIs. Using URIs in name
> actually not treating them as URIs (as proposed by some - comparing
> URIs as strings irrespective of their base address) is simply technically
> broken

I don't know why I'm stepping into this morass, but somebody has to start it
off, I guess. I haven't followed the XML Plenary discussion all that
carefully, but here's my understanding of why Tim Berners-Lee's conviction
is not widely shared:

The gist of Tim's message seems to be that *absolute* URIs are at the very
foundation of the Web and give it and the W3C specs much of their power.  I
doubt if anyone seriously disagrees.  But *relative* URIs are only a
convenience mechanism, and as often happens, their convenience hides their

Allowing relative URI's in namespaces that must somehow get resolved back to
an absolute URI that may or may not point to a resource adds a fair amount
of complexity to the specification and implementation of various XML-related
specs. (I *know* that the DOM WG has wrestled with the complexities of
namespace prefixes, names, URIs, and presenting a useable interface to the
user for much of the last year).  Furthermore, it entangles the IETF URI
specs with various W3C constructs (XML, namespaces, xml:base, etc.) in ways
that are difficult for even experts to fully comprehend.  Finally, the end
result is to give end users even more rope with which to hang themselves,
ultimately decreasing the integrity of the Web in actual practice.

So the alternatives appear to be: to forbid relative URIs in namespaces,
which seems arbitrary and inconsistent with various implementations out
there already (most notably Microsoft's); or to rework the namespace spec to
say that a "namespace name" is not a URI, just some string believed to be

> It is really important for electronic
> commerce and, ideeindeed, the whole future of the web, that XML documents
> defined in terms of namespaces which are considered to identify the
> of the language they are written in.

This is the very essence of the issue.  There is a widespread opinion that
as a practical matter, in a world of less than perfectly understood specs
and less than perfectly coded implementations, it is far easier to identify
what a namespace REALLY means by making it completely specified by the
namespace name without reference to the URI resolution mechanism.

Again, I claim no particular expertise here, just a desire to get the
discussion going and this issue put to rest, one way or the other.
Received on Monday, 15 May 2000 13:33:04 UTC

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